The invention relates to a spreadable medical instrument, comprising a handle part and at least two spatula elements which are connected to said handle part and, via at least one adjusting mechanism, can be adjusted parallel or at an angle to one another between an initial position, in which the spatula elements rest against one another, and at least one working position. In the working position, the individual spatula elements are spaced at intervals so that they form lateral gaps at least in the distal area, and when the spatula elements are in a working position, these lateral gaps between the spatula elements can be covered almost entirely by swiveling flap elements.
Laryngoscopes are used particularly for direct instrumental inspection of the larynx as well as for endolaryngeal surgical interventions. Laryngoscopes are basically broken down into fixed and spreadable laryngoscopes. With a fixed laryngoscope, the spatula part connected to the handle part takes the shape of a tube, which is closed or possibly unilaterally slit, hollow and basically cylindrical, and which has a constant lumen for the introduction of appropriate medical instruments. Fixed laryngoscopes have the disadvantage that, on the one hand, the lumen cannot be enlarged on demand and, on the other hand, it is nevertheless necessary to introduce the laryngoscope with its nonadjustable lumen into the mouth and pharynx of the intubated and anaesthetized patient.
These difficulties can be avoided by employing spreadable laryngoscopes. These laryngoscopes feature a spatula part connected to a handle part and consisting of at least two spatula elements, which can be adjusted in relation to one another, and whose lumen can be adjusted between an initial position for the introduction and removal of the laryngoscopexe2x80x94with the spatula elements as close to each other as possible, and a working position, in which the individual spatula elements are adjusted parallel and/or at an angle to each other. When adjusting the individual spatula elements parallel and/or at an angle to each other, gaps are created between the individual spatula elements, at least in the spatula elements"" distal area. Yet the configuration of this gap has the disadvantage that soft parts, such as the cheek or tongue, can pass through these lateral gaps into the laryngoscope""s interior space, exposing them to possible injury, while also considerably reducing the surgeon""s working space.
In order to prevent soft parts from penetrating into a spreadable medical instrument during surgery, it standard practice to keep the gap closed by pressing an additional spatula from the instrument""s inner side. It has also proved helpful to roughen the spatula elements"" outer surface, which prevents the tongue, for instance, from slipping laterally. The use of an additional spatula considerably reduces the free lumen at the surgeon""s disposal and also necessitates the help of an assistant. The spatula elements"" roughened outer surface also makes it difficult to clean the medical instrument so that, to some extent, this model too can be considered disadvantageous.
A typical spreadable medical instrument is known from U.S. Pat. No. 5,868,668 A. With this known medical instrument, the flap parts that cover the lateral gap are connected to the handle part so as to swivel and occupy the spatula elements"" initial position between these spatula elements. Only after the spatula elements have been spread into a first open position, can the flap elements be swiveled into the position where they cover the lateral gap, at least partially. Yet since the flap elements cannot be actuated during the spatula elements"" initial opening, it is possible for tissue to slip in between the spatula elements and to reduce the surgeon""s working space. This known instrument has the further disadvantage of forcing the surgeon to swivel the flap elements manually by further spreading the spatula elements and, in addition, of requiring that the spatula elements be kept open by continuous manual intervention.
WO 98/33431 also demonstrated how to cover the spatula elements, which can be adjusted to each other, with a sleeve made of elastic material, which stretches when the individual spatula elements are being adjusted to each other, thus closing the lateral gap between the spatula elements. This method for closing the lateral gap has the disadvantage that, thanks to the stretchable, elastic material that envelops the spatula elements, the effort needed to adjust the spatula elements to each other, on top of the pressure exerted by the surrounding tissue, is considerably increased and thus the spatula elements are permanently under pressure to snap back into the closing (initial) position. In addition, there is the risk that during the introduction of the surgical instruments as well as during laser surgery, the elastic material becomes damaged, thus canceling, or at least reducing, its protective effect.
Based on this state-of-the-art, it is the purpose of the invention to develop a spreadable medical instrument of the initially described type, in such a way that its easy application, in a simple and reliable manner, prevents soft tissue from entering through the lateral gap between the spread spatula elements.
The solution provided by this invention is characterized in that the swiveling flap elements of each side are each fixed to at least one spatula part in such a way that, in the initial position of the spatula elements, they rest in a form-fitting manner on the outside of the other spatula part that is not equipped with the respective flap element.
Securing the flap elements of each side to at least one spatula part each, as provided by this invention, ensures that the flap elements are ready from the onset of the opening movement of the spatula elements and immediately close the emerging lateral gap without requiring a separate actuation of the flap elements. Since, in the initial position, the flap elements rest in a form-fitting manner on the spatula elements, and since the spreading spatula elements swivel them into a position where they cover the gap, an instrument designed in this manner offers the surgeon, at all times, an open cross-section in which to operate.
The form-fitting attachment of the flap elements to the spatula elements facilitates the introduction and removal of the spreadable medical instrument in its initial position, since the medical instrument""s circumference, increases only slightly in comparison to an instrument without flap elements, but still is considerably smaller than the circumference of a fixed endoscope with a comparable operating cross-section.
Based on a practical embodiment of the invention, it is further proposed that the flap elements swivel automatically over the spatula elements that are adjustable to each other. This automatic closing of the lateral gap does not require additional manipulations or other measures, so that the surgeon has greater freedom of movement.
Another advantageous proposal is to fix the flap elements to the spatula elements in such a way that they can be detached, which further simplifies cleaning.
A preferred embodiment of a spreadable medical instrument with two spatula elements that can be adjusted to one another proposes that one spatula element be secured rigidly to the handle part while the other spatula element is connected to the handle part in an adjustable manner, parallel and at an angle to the secured spatula element, and one swiveling flap element is secured to each longitudinal side of the rigidly secured spatula element. The configuration with one rigidly secured and one adjustable spatula element enables an especially simple adjustment mechanism to adjust the position of the spatula elements in relation to each other.
The operation of the flap elements can be further simplified by spring-loading them in their initial position next to the spatula elements. This ensures that the flap elements immediately return to their position interlocking with the spatula elements as soon as the spatula elements are closed again.
The height of the swiveling flap elements of this invention is calculated in such a manner that at least part of each flap element in the working position of the spatula elements fits close to the outer surface of the spatula element which is not equipped with this particular flap element. This prevents the flap elements from tilting inside between the spatula elements and blocking any readjustment of the spatula elements to their initial position.
In addition, the invention proposes that the outer surfaces of the spatula elements and/or the flap elements be smooth. Because of the use of flap elements, which close the lateral gap, it becomes unnecessary to roughen the outer surfaces, so that such a spreadable medical instrument can be easily and thoroughly cleaned.
Finally, the invention proposes that the spreadable medical instrument be a laryngoscope.